The Rejection Connection
Why are so many children having allergic reactions to food?

By Katrina Mather

Soon after feeding her then 2-year-old daughter, Rebekah, a small amount of bread with peanut butter on it, Judy Silver witnessed her worst imaginable nightmare. “Within minutes, my daughter was on the floor, kicking and gasping for air,” recalls the Ridgefield, Connecticut, resident. “I could tell she was worsening by the minute. I thought she was having a seizure and dying.”

Silver immediately called 911, but she feared the ambulance might take too long. So she put Rebekah in the car and drove to the pediatrician’s office 15 minutes away, where medical staff administered epinephrine and reversed Rebekah’s symptoms. Rebekah had had an anaphylactic attack—a sudden, severe, systemic allergic reaction—to peanuts.

Up to 8 percent of children younger than 3 are affected by food allergies.
Source: Food Allergy & Anaphylaxis Network (FAAN). Reactions like Rebekah’s account for 30,000 visits to emergency rooms and 150 to 200 deaths among children and adults each year. The Food Allergy & Anaphylaxis Network (FAAN) in Fairfax, Virginia, estimates about 3 million teens and children younger than 18 have food allergies. More specifically, a new study published in the Journal of Allergy and Clinical Immunology indicates a doubling of reported peanut allergies in children from 1997 to 2002 (2003, vol. 112, no. 6). “This study confirms what we’ve been hearing from growing numbers of families, school administrators, and other institutional leaders—food allergies are increasing,” said Anne Muñoz-Furlong, founder and CEO of FAAN.

Physicians also report seeing more and more children with food allergies in their offices during the past few years—and the upward trend isn’t expected to stop anytime soon. “The number of all allergic disorders, including asthma, eczema, and hay fever, has increased in recent years,” says Scott H. Sicherer, MD, assistant professor of pediatrics at Mt. Sinai School of Medicine’s Jaffe Food Allergy Institute in Manhattan. “There is a definite impression of an increase in the number of people with food allergies, a broader spectrum of illness due to food allergies, and an increase in the number of foods to which people are allergic.”

Studies show that most food allergies are acquired within the first two years of a child’s life.
Source: Pediatrics, 2003, vol. 111, no. 6. Research is ongoing to better understand the medical and environmental reasons behind these increases and to explore prevention and treatment options. Such research is especially important for food allergies that cause life-threatening reactions, which can occur in susceptible individuals after ingesting as little as 1/1000th of a peanut, for example, or sometimes even from breathing the dust of an allergenic food or touching someone who has eaten an allergenic food. Although not all allergies induce life-threatening reactions in children, peanut allergies often do, and no parent—or anyone else—wants to risk seeing or reliving an anaphylactic episode in their child.

The allergy puzzle
The current surge in allergic children isn’t easy to explain or understand. Experts offer different theories. “What foods we consume, how early in life we consume them, how frequently we consume them, and in what form we consume them are all factors in the cause of food allergies,” explains Sai Nimmagadda, MD, an allergist with Associated Allergists and Asthma Specialists and attending physician at Children’s Memorial Hospital in Chicago.

Food fears: Milk, eggs, peanuts, wheat, soy, and tree nuts (such as walnuts, pecans, and almonds) account for 90 percent of food allergy reactions in children. Peanuts, tree nuts, eggs, milk, shellfish, and fish can cause life-threatening reactions. For example, peanuts and peanut butter are widespread favorites in the American diet, and many new moms are eating peanuts in some form and feeding very young children peanut butter. The problem is, peanuts have stable proteins that are not easily digested by young children. In addition, a recent study reported in the Journal of Allergy and Clinical Immunology (2001, vol. 107, no. 6) showed that roasting peanuts—which is how most peanut butters are made—actually makes the allergen resistant to the effects of digestive enzymes. Other studies have shown that peanut protein (as well as milk, egg, and wheat proteins) is secreted in the breast milk of women who have eaten these foods.

All or some combination of these factors theoretically can mean that children susceptible to a peanut allergy are receiving their first exposure to peanut protein early in life, before their immune systems have matured. This could result in sensitization and the greater likelihood of a reaction with every repeated exposure.

Of course, “susceptible” is the operative word here because for a food allergy reaction to occur, a child must be genetically predisposed to form food-specific immunoglobulin E (IgE) antibodies to foods, resulting in a sensitization to the food. “Studies show that allergies run in families,” says Sicherer. Indeed, if there is a family history of allergy—not limited to food allergies, but any allergy with an IgE-mediated immune response—the estimated risk of a child being predisposed to develop an allergic disease increases.

In addition, some experts say that today children are introduced to a wide variety of more complex foods, thus increasing the chances of producing an allergic reaction. “When I was a child, there was basically one teething biscuit,” notes Amie Rappoport, administrative director of the Food Allergy Initiative, a Manhattan-based nonprofit organization that raises funds for research devoted to finding a cure for life-threatening food allergies. “Today, parents may hand their teething child part of a sesame bagel, Honey Nut Cheerios, or any number of different foods that could trigger a reaction.” There is also the hygiene hypothesis, compelling to many experts in the food-allergy field, though scientific evidence is lacking. “The hygiene hypothesis suggests that people in industrialized countries, with their widespread use of antibiotics and zealous sanitation measures, have changed the environment such that their bodies are not dealing with as much natural infection as in earlier days,” explains Sicherer. This could mean the immune system, which is primed and ready to build itself up by fighting bacteria, instead mistakenly turns against substances that otherwise would not be detected as potentially harmful. “Genetics, the environment, and the interaction between the two are complicating factors in the cause of food allergies,” says Sicherer.

What can be done?
As of yet, no widely accepted allergy prevention methods exist. Avoiding early exposure to potential allergens is one of the only courses parents can take today, although there are efforts to develop drugs that would help at-risk children build up antibodies.

Many doctors recommend that if a family has a history of allergies, parents should take special care as to when to introduce certain foods to their child. “If there is a compelling history of allergy in a family,” says Nimmagadda, “I recommend peanuts be avoided in the third trimester of a woman’s pregnancy, during breast-feeding, and until the child is 3 years old.”

Along those lines, the American Academy of Pediatrics (AAP) recommends that almost all infants be breast-fed exclusively for the first six months, regardless of a family history of food allergies. However, the AAP advises mothers with infants who are susceptible to allergies to eliminate highly allergenic foods from their own diets while nursing, and then introduce these foods later on a specific timeline. (For more detailed guidelines, go to www.foodallergy.org/downloads/prevention.pdf.) Sicherer stresses the effect of following this recommendation is uncertain, however, and says mothers should design a feeding strategy in partnership with their doctors.

Sleuthing an allergy

  •  
  • Keep a diary of your child’s symptoms and their context.
  • Ask your doctor about an elimination diet.
  • Take a skin-prick test, in which a needle pushes a tiny amount of a food extract into the skin (usually the back), which may cause a wheal (bump) to develop within 15 minutes.
  • Order a blood test in which your doctor sends a sample of blood to a lab, where it is combined with a food protein and analyzed for IgE antibodies.
  • Inquire about a monitored food challenge, usually conducted in a hospital.

—K.M.

Note: These actions should be done in consultation with a child’s pediatrician or allergist.

Source: American Academy of Allergy, Asthma, and Immunology’s The Allergy Report.

Researchers are also active in the quest for a food-allergy vaccine. “A vaccine is akin to a cure,” says Rappoport. “It changes a person’s immune response by turning off a person’s reaction.” Researchers are studying different delivery mechanisms, and Rappoport says the goal is to find a cure by 2010. Another imminent treatment option for a child who already has a peanut allergy is referred to as “anti-IgE,” wherein anti-IgE antibodies bind to IgE in a patient’s bloodstream and block an allergic response. “This drug would be a monthly safety injection, creating a buffer between a peanut-allergic person and peanuts,” says Rappoport. “It would ease people’s fear of accidental exposure to peanuts by giving them an increased tolerance, so instead of having a severe reaction after ingesting a minute amount of a peanut, they may be able to withstand several peanuts or more without having a reaction.” One anti-IgE drug, Xolair, originally developed and available by prescription for severe allergic asthma, is expected to be used in clinical trials for peanut allergies this winter to test for the drug’s efficacy, safety, and the appropriate dose for use in patients with severe peanut allergies. Preliminary studies of a similar drug showed no significant side effects. Although availability of the drug would be important and exciting, it would not be a cure.
 

And finally, the Food Allergy Initiative is funding other studies of traditional Chinese herbal treatments that may emerge as promising nutraceuticals. Various herbs are being tested. “The number of effective herbs has been narrowed down to three,” says Rappoport. “Now researchers are analyzing what parts of those herbs are turning off allergic reactions in peanut-allergic mice.” The next steps will be to conduct clinical trials and determine how to convert the findings into doses and preparations that can be commercially manufactured.

Resources

Allergic-Child
www.allergicchild.com

American Academy of Pediatrics
www.aap.org

Food Allergy & Anaphylaxis Network (FAAN)
www.foodallergy.org

Food Allergy Initiative
www.foodallergyinitiative.org

Parents of Food-Allergic Kids (an online support group)
http://groups.yahoo.com/group/POFAK

Living with a food allergy
Although current medical research provides hope, the reality of day-to-day living for children with food allergies and their parents can be challenging. Currently, avoiding allergenic foods is the only way to prevent a reaction, which can sometimes make the world look like a minefield. “After Rebekah’s diagnosis, I looked in my kitchen and was amazed by how many foods had peanut or tree nut ingredients,” recalls Silver. “I was upset and angry and saw food as the enemy for a while.” Reading each and every food label is essential to avoiding a child’s allergenic food—and it can be a daunting task. “For example, the ingredient ‘natural flavor’ could be milk or peanut protein,” says Sicherer. “In some cases, parents need to call a company to find out exactly what ‘natural flavor’ is before deciding whether it’s safe to feed their child.”
 

Allergenic substances can also appear in unexpected places (such as wheat in a certain brand of hot dog, soy in a hot-cocoa mix, or peanuts in canned soup) and have unexpected names (for instance, “albumin” may indicate egg protein, and “whey” and “casein” indicate the presence of milk protein). In addition, there is a risk of cross-contamination in restaurant-prepared and packaged foods in particular, meaning that utensils, pots, or machinery used for one food may also be used for another, with residue from the first food remaining on the shared equipment. Consequently, many parents of children with food allergies often avoid eating out.

Avoidance of food allergens is also made more challenging because allergens can show up in nonfood items and still be a threat. “Parents have to think beyond just food,” says Susan Leavitt of Manhattan, whose son David Parkinson has many food allergies, “and check labels of items such as soaps, shampoos, and lotions, which can also contain allergens.” Parents—and schools—must also think about allergenic foods, especially peanut butter and eggs, showing up in arts-and-crafts projects. For instance, an alert parent found an interactive display at a museum consisting of “sand” that was made of ground walnut shells, which can cause reactions simply from skin contact.

“When you first take in the implications of your child’s diagnosis of food allergy, you wonder how he will be able to go anywhere safely and how you’ll be able to function into the next week,” says Leavitt. Thanks to educational resources and support groups, more help than ever is available for parents of children with food allergies (see “Resources” for more information). Still, parents have ongoing struggles with enlisting help and understanding from people—even relatives—who spend any time supervising their child in situations where food may be present.

These struggles can be particularly acute when parents inform the school of their child’s allergies, “which parents absolutely must do,” says Muñoz-Furlong. Although some schools have initiated peanut bans, FAAN advocates a spirit of cooperation that includes strategies for avoidance and emergency treatment plans worked out among parents and school staff.

Many tough situations can be solved with creative, practical solutions, whether it’s designating a “peanut-free” or “peanut-only” table in the school cafeteria or having a ready supply of allergen-free cupcakes in your freezer for your child to take to a friend’s birthday party. Happily, some children will outgrow their food allergies. In fact, most children allergic to milk, egg, or soy will outgrow those allergies by age 3. Although studies show that up to 20 percent of young children may outgrow a peanut allergy, fish, shellfish, and tree nut allergies are usually lifelong. An allergist should determine if your child has outgrown an allergy.

“No parent should have to live in fear about every bite of food their child takes, every hand their child holds, and every kiss their child receives,” says Rappoport. Dedicated efforts of the medical community and parents of children with food allergies are working to shift that level of fear from reality to memory.

San Francisco–based freelance writer Katrina Mather specializes in food and health topics.